Warner Bros. Studio Tour London has the ACTUAL sets, props, costumes, etc from the movie! We spent about 4 hours here with our kids, and could have spent more if we didn't come so close to closing time.

It's cheapest to buy tickets directly on the Warner Bros studio tour website, but if they're sold out (they book far in advance) then you can use get your guide or Viator, it just might be more expensive.

The only place to get butterbeer is at the cafe in the middle of the tour so be sure to stop!